Makkari is a member of the immortal race the Eternals,
who are the creations and servants of the Celestials. Makkari is a relatively
young Eternal, both in age (only 4500+ years old) and in outlook. He has
superspeed and an interest in moving fast and things that move him quickly.

It was revealed that, during the Golden Age, Makkari had masqueraded
first as the superhero Mercury,
then as the superhero Hurricane,
and then as FBI Agent Jake Curtiss, working against the Deviants and, presumably,
on other missions. His history before he began being Mercury and the time
after the events in Marvel Universe but before Eternals #5
has not been recorded, for the most part, but we do know that he met Plato
and Elvis and that he was a member of the First
Lineas "Major Mercury."